LymeDisease, by Jeffrey Eiden, MD, Family Medicine, Putnam County Primary Care
It is tick time again! Along with the warmer weather that gets us outside, hiking and tromping through the woods, comes the risk of exposure to ticks. When we think of ticks, we often think of Lyme disease. Here is a brief review of what you should know about ticks, preventing and treating tick bites, as well as some information about Lyme disease.
A tick is a small arachnid that is a parasite. Ticks require the blood of another organism to survive. They attach to a host, often a mammal, feed on blood, detach and repeat when they need another meal. Not all ticks carry diseases, but some do. There are 16 known human diseases transmitted by ticks. The best approach is to avoid ticks if possible or at least remove them soon after they attach.
Ticks are most active during warm weather. They are most often in wooded or brushy areas or in high grass. Be aware that you might encounter ticks when in this type of area. If you venture into an area that is likely to have ticks present, you should consider using a tick repellent. Most insect repellents also repel ticks. The recommendation is to use an insect repellent that contains DEET. Clothing, boots and tents can also be pre-treated with 0.5% permethrin which also repels ticks. Limiting exposed skin by covering it with clothing and by tucking pants into socks keeps ticks from finding a place to attach.
If a tick does attach, it is best to remove it as soon as possible. Get in the habit of checking for ticks after spending time outdoors. Look for ticks on clothes and shoes. Check pets also, as ticks can attach to them and then gain access to your home. It is also wise to bathe or shower within two hours of returning inside and to check over all your skin to be sure there are no ticks attached. Children should be thoroughly checked by parents.
When a tick is found on skin, remove it. The best way to remove a tick is to grasp it firmly with fine-tipped tweezers and pull away from the skin. It works best if the tip of the tweezers is as close to the skin as possible. Steady pressure should remove the tick. Avoid twisting or jerking. If the tick does not come off in one piece, remove the pieces left behind if possible. There are some “tricks” for removing ticks that are passed around, including using a match or nail polish. These do not work. Use the tweezers and pull.
Suppose you do find a tick that has attached to your skin. Remove it as above. Do not panic but do be alert for any signs or symptoms of tick-borne illness. These would include fever, chills, muscle aches and in some cases, rash. If any of these symptoms develop, contact your primary care provider for instructions.
Shifting to Lyme disease, the risk of getting Lyme disease from a tick bite is very low (about 1 in 100) if the tick is removed before it is engorged. This is why it is so important to find and remove ticks as soon as possible.
There is consideration for using a single dose of antibiotic to prevent Lyme disease after a tick bite, but this is only recommended in specific situations. The tick would need to be identified as a deer tick, as this is the only type of tick known to transmit Lyme disease. Deer ticks have black legs, which distinguishes them from other types of ticks. The tick should have been attached for 36 hours or more, as indicated by time since exposure or degree of engorgement. The antibiotic should be given within 72 hours of tick removal. The tick bite should have occurred in an area where at least 20% of ticks are infected with the bacteria that causes Lyme disease. This is an issue in parts of New England and parts of Pennsylvania, New Jersey, New York, Minnesota and Wisconsin. In Ohio, although we have deer ticks and some carry Lyme disease, we are not yet at area with this level of tick infection.
Another approach to preventing full-blown Lyme disease is to treat at the first sign of a rash that indicates possible infection. This rash is distinctive. It occurs at the site of the tick bite and is salmon to red-colored and circular. One-third of the time, it can have a clear area in the center that makes it look like a bull’s eye or target. The rash, called erythema migrans, tends to expand outward over several days, getting larger and larger. If you have had a tick bite and develop this type of rash where the bite occurred, you should call your primary care provider and be evaluated. Treatment at this point would typically be with a course of an antibiotic like doxycycline, amoxicillin or cefuroxime.
Lyme disease is caused by the body’s immune response to the bacteria Borrelia burgdorferi. The symptoms are divided into different phases, based on length of time since initial infection. The early localized phase of Lyme disease is usually about 7-14 days after the tick bite. It is characterized by the rash of erythema migrans, and symptoms typical of a viral infection, such as fatigue, fever, headache, muscle or joint pain and swollen lymph nodes. The symptoms are not often severe.
The early disseminated phase of Lyme disease occurs days to weeks after the tick bite and is caused by the spread of bacteria through the bloodstream, leading to inflammation in the affected area. There can be involvement of the heart or nervous system. Symptoms of infection in a particular organ are not common, but can be severe.
In addition to early symptoms, there can be a late phase of Lyme disease. This most commonly is seen as inflammation affecting the joint and muscles and happens in 80% of people who did not receive treatment with antibiotics for their early infection. Late Lyme disease can also cause neurologic symptoms, but this is rare.
Post-Lyme disease syndrome is a group of symptoms that can occur chronically after treatment for Lyme disease. The symptoms seen with this are headache, fatigue and joint pain. Because these types of symptoms are common, some people worry that they have post-Lyme disease syndrome even when they do not have a history of having had Lyme disease. It is not helpful to treat the post-Lyme disease syndrome with antibiotics, and it gradually resolves.
The diagnosis of Lyme disease is made based on history of possible exposure to ticks, characteristic signs and symptoms, and the finding of antibodies to Lyme disease on blood testing. The blood tests are not always helpful and should be ordered by a physician/provider after consultation and interpreted considering the patient’s story and symptoms.
As in so many medical conditions, prevention is key and early detection/treatment is the next best option. Watch out for ticks! But get outside and enjoy the warm weather whenever you can. Doctor’s orders. J